The Spinosaurs are a group of carnivores that originated in the early Cretaceous and then died out around the beginning of the late Cretaceous. They where relatively lightweight, and had relatively weak jaws with concise teeth. The relatively is compared to the tyrannosaurs, which is really an unfair comparison. Most of them had sails, and it is almost certain that they ate fish. The Spinosaur above is Baryonyx.